COSTS TO CONVERT TO CLASS-A: COLUMBUS BIOSOLIDS FLOW-THROUGH THERMOPHILIC TREATMENT (CBFT3) AS A COST EFFECTIVE OPTION

Like many utilities across the country, the Columbus Water Works (CWW - Columbus, GA) has found much of the previously available land for biosolids application to be inaccessible due to a number of reasons, including public concerns over potential pathogen contact. In response to these concerns, CWW considered a number of currently available processes to further reduce pathogens (PFRPs) and operational options for achieving Class-A biosolids quality allowed in the 40 CFR, Part 503 regulation. A new, possibly-equivalent PFRP was identified to be very cost-effective for retrofit to an existing treatment plant with existing anaerobic digesters. Development of a PFRPE-quivalent process would require considerable research effort and negotiation with the Pathogen Equivalent Committee (PEC) of the USEPA. The potential capital and operational savings predicted from the nationwide application of this new technology was determined to be worth the effort. The treatment technology has been named “Columbus Biosolids Flow-Through Thermophilic Treatment” (CBFT). This paper provides a comparison of the costs required to convert plants of various sizes to the CBFT process and other currently available PFRPs.